CK5
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I found removing the secondary spark wires from the coil allows me to remove from the plugs much easier, no breakage.
My thinking atm is the intake didn't seal on that side.
 
Understand but as you pointed out previous issue.
Another thought, possibly the engine was left to lay on that side for a period of time and oil was able to seep into combustion chambers
 
It barely smoked when it first fired so there wasn’t much oil in the cylinders.

My friends were telling me it smelled rich on both trips. However it will intermittently get worse, as if all cylinders aren’t firing. It was running like that when I parked it so I thought it was best to pull the plugs for a reading. I actually expected to find one or two cylinders Rich, possibly from an ignition failure. I suppose it’s possible the passenger bank of coils isn’t firing?
 
It barely smoked when it first fired so there wasn’t much oil in the cylinders.

My friends were telling me it smelled rich on both trips. However it will intermittently get worse, as if all cylinders aren’t firing. It was running like that when I parked it so I thought it was best to pull the plugs for a reading. I actually expected to find one or two cylinders Rich, possibly from an ignition failure. I suppose it’s possible the passenger bank of coils isn’t firing?
That seems more like it.
 
I’m not sure without looking at diagrams, but usually each bank has its own fused power.
 
I have spark on the left bank with the fouled plugs. Fuel pressure is @58 with the ignition on.
 
What side is the fuel inlet on? I know on a ls with stock injectors the passenger bank will run lean with a good tune.
 
What side is the fuel inlet on? I know on a ls with stock injectors the passenger bank will run lean with a good tune.

Fuel enters through the drivers bank. It’s just a Howell ECU with the smog crap removed. Howell harness with the stock injector and coils harnesses retained.
 
State Of The Union Congress GIF by PBS News

I’m not sure without looking at diagrams, but usually each bank has its own fused power.
When I built my 8.1 harness, each cylinders injector is fired straight from the ecm, there wasn't any bank to speak of.
Mine originated from an 03 Silverado
 
State Of The Union Congress GIF by PBS News


When I built my 8.1 harness, each cylinders injector is fired straight from the ecm, there wasn't any bank to speak of.
Mine originated from an 03 Silverado
Each ground/trigger pulse is fired from the ecm directly but the power is usually paralleled.
 
Each ground/trigger pulse is fired from the ecm directly but the power is usually paralleled.
When I wired it, it had 2 or 3 different battery power inputs, and at least that many switched power inputs. I'm not really sure what we're talking about. Mine just had battery hots, switched hots, and several grounds.
And at that, all those hots were fed from the same power strip.
 
I was really hoping to find the coil harness installed ass backwards however no such luck. I verified 12v and the ground is good at each coil plug. Does anyone know if the ignition control wire (signal) is 12v or ground? At this point I haven’t found the smoking gun.

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Is it possible the O2 sensor or wiring for bank 2 is the cause? I’m interested to see the live data from the scan tool however I’m waiting on plugs and new wires before I can run it again.
 
That is an additional (potential) issue.
If your harness is built for only 2, O2 sensors, atleast in my harness, all the other O2 sensor grounds have been connected together, and are grounded to a single point in the ecm. I don't remember which ones they are off the top of my head. But, I would think all these harnesses are similar in function. Don't know if it matters. It shouldn't, because all the other O2 sensors unputs have been deleted at the ecm also. But, I do remember the guy from LT1SWAP.COM saying that all the other ground had to be connected to a common ground, that went back to the ecm. It was a PITA, as 6 different wires going into one. Yeah, that makes this disaster of a connection in the middle of the harness.
 
I was thinking O2’s as well. Be interesting to see the data for sure.
Lots of chatter about this from the LS crowd.

That is an additional (potential) issue.
If your harness is built for only 2, O2 sensors, atleast in my harness, all the other O2 sensor grounds have been connected together, and are grounded to a single point in the ecm. I don't remember which ones they are off the top of my head. But, I would think all these harnesses are similar in function. Don't know if it matters. It shouldn't, because all the other O2 sensors unputs have been deleted at the ecm also. But, I do remember the guy from LT1SWAP.COM saying that all the other ground had to be connected to a common ground, that went back to the ecm. It was a PITA, as 6 different wires going into one. Yeah, that makes this disaster of a connection in the middle of the harness.

The Howell harness uses one O2 on each bank.

One of the O2 sensors I received was wrong and I didn’t want to wait for a replacement so I have a parts store O2 sensor on bank 2. I eventually received the replacement O2 (Delphi) and its sitting on my work bench.
 
I built my 8.1 harness from 2003 silverado 6.0 harness. It's what I had.
LT1SWAP.COM reprogrammed my ecm. Using only 1, O2 sensor per bank. I'm willing to bet that our ecm's are very similar.
I was told that if that common ground is messed up it will cause a code an cause the engine to run rich. I don't remember much else about them
 
Lots of chatter about this from the LS crowd.



The Howell harness uses one O2 on each bank.

One of the O2 sensors I received was wrong and I didn’t want to wait for a replacement so I have a parts store O2 sensor on bank 2. I eventually received the replacement O2 (Delphi) and its sitting on my work bench.
Same principles they both work the same right? Seems like Howell isn’t what they used to be and the quality has gone down.
 

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